Center for Computational Quantum Chemistry, Department of Chemistry, University of Georgia, Athens, GA 30602-2525 (USA).
Present address: Hanse-Wissenschafts-Kolleg (Institute for Advanced Study), Lehmkuhlenbusch 4, 27753 Delmenhorst (Germany).
Angew Chem Int Ed Engl. 2015 Aug 10;54(33):9468-501. doi: 10.1002/anie.201410407. Epub 2015 Jun 26.
The idea of planar tetracoordinate carbon (ptC) was considered implausible for a hundred years after 1874. Examples of ptC were then predicted computationally and realized experimentally. Both electronic and mechanical (e.g., small rings and cages) effects stabilize these unusual bonding arrangements. Concepts based on the bonding motifs of planar methane and the planar methane dication can be extended to give planar hypercoordinate structures of other chemical elements. Numerous planar configurations of various central atoms (main-group and transition-metal elements) with coordination numbers up to ten are discussed herein. The evolution of such planar configurations from small molecules to clusters, to nanospecies and to bulk solids is delineated. Some experimentally fabricated planar materials have been shown to possess unusual electrical and magnetic properties. A fundamental understanding of planar hypercoordinate chemistry and its potential will help guide its future development.
一百多年来，平面四配位碳（ptC）的概念一直被认为是不可信的。直到 1874 年之后，ptC 的例子才被计算预测和实验实现。电子和机械（例如小环和笼）效应稳定了这些不寻常的键合排列。基于平面甲烷和平面甲烷二阳离子的成键模式的概念可以扩展到其他化学元素的平面超配位结构。本文讨论了各种中心原子（主族和过渡金属元素）具有多达十个配位数的无数平面构型。从小分子到团簇、纳米物种到块状固体，详细描述了这种平面构型的演变。一些实验制备的平面材料已被证明具有异常的电和磁性质。对平面超配位化学及其潜力的基本理解将有助于指导其未来的发展。
